Menghitung sudutno ngasal y​

< QNO = 100°

<NOP = 1/2 x (360° – 2x<NOP)

= 1/2 x (360° – 2 x 100°)

= 1/2 x (360° – 200°)

= 1/2 x 160°

= 80°

<OPQ = <QNO = 100°

<PQN = <NOP = 80°